The invention relates to a device for a directed supply of primary combustion air into the coking chamber of a coke oven of the “Non-Recovery” or “Heat-Recovery” type, wherein primary combustion air is ducted through one or several entry ports in the coke oven top or in the front-end or rear-end coke oven chamber wall, and wherein the entry port(s) is (are) equipped with devices through which the entry stream of primary air is directed so that the primary air is better distributed in the gas-filled space over the coke cake. The invention also relates to a method for operating a coke oven chamber or coke oven battery or coke oven bank, wherein the primary combustion air for coal carbonization enters through one or several entry port(s) in the top of a coke oven chamber or through one or several entry port(s) in the coke oven chamber wall of a coke oven or through one or several entry port(s) in the coke oven chamber door of a coke oven chamber into the gas-filled space above the coke cake, with the coking gas from coal carbonization utilized for combustion also being ducted into said gas-filled space, and wherein the primary air streams to the coke cake at an angle of less than 90° in vertical direction and at an angle of more than 0° in horizontal direction.
Production of coke from coal or carbonaceous materials is frequently performed in coke ovens of the “Non-Recovery” or “Heat-Recovery” type. With coke ovens of the “Non-Recovery” or “Heat-Recovery” type, coal is heated to high temperatures, and the evolving coking gas is combusted with an under-stoichiometric quantity of so-called primary air. In general, combustion with primary air is incomplete and occurs in a gas-filled space above the coke cake, which is called the primary heating space. Proceeding from this gas-filled space, the incompletely burnt coking gas is ducted into so-called “downcomer” channels into secondary air soles located beneath the coking chamber where secondary air streams in and where the incompletely burnt coking gas is completely combusted. In this manner, a more uniform heat distribution of the entire coke cake is achieved. With the “Heat-Recovery” type, the heat from combustion is additionally exploited to generate energy.
In general, the introduction of primary air into the primary heating chamber is accomplished through openings in the top of a coke oven chamber or in the vertical coke oven chamber wall which is located above the coke oven chamber door. In a frequently encountered layout, the coke oven chambers are closed by coke oven chamber doors which are mounted at the front-end coke oven chamber wall, which is also called pusher side coke oven chamber wall, as well as at the rear-end frontal coke oven chamber wall, which is also called coke side coke oven chamber wall, in order to allow for charging and cleaning of a coke oven chamber. To minimize heat losses during charging, the doors of coke oven chambers are so mounted that they only seal the coke oven chamber bottom section which is charged with the coke cake. The upper section of the coke oven chamber which in its interior encompasses the gas-filled space is covered externally at the frontal walls by the coke oven chamber wall. In a typical layout, this part of the coke oven chamber walls which is located above the coke oven chamber doors is comprised of openings which—in addition to the openings in the top of the coke oven chamber—are utilized for introducing primary air into the gas-filled space above the coke cake.
Likewise, there are prior art layouts for coke oven chambers, the frontal coke oven chamber door of which closes the entire coking space and, more particularly, the gas-filled space in the interior of the coke oven chamber towards the exterior. The coke oven chamber door then encompasses nearly the entire frontal coke oven chamber wall. This may be the case both on the pusher side and coke side frontal coke oven chamber walls as well as on both sides. Entry ports for primary air may also be located in the doors of these layouts.
The German patent description DE 102008025437.1 which has not yet been disclosed at the moment of this application describes a device which is utilized for a directed introduction of primary air into the gas space of a coke oven chamber, with said device being comprised of openings launched into the top of a coke oven chamber and with these openings having an opening-outwardly directed stream-out angle relative to a vertical plumb through the top, said angle being an opening angle and being greater than 0°. Owing to this shape, primary air is better distributed in the gas space above the coke oven so that the combustion of coking gas in this area is improved. Though the teaching allows for an intensified intimate mixing of primary air and coking gas in the area of the gas space lying over the coke cake and being near the entry port, there is some need for improvement relative to a further intensified intimate mixing of primary combustion air and coking gas in the gas space areas further away from the entry ports.
Opening ports for supply of primary air frequently are so designed that they admit primary air vertically onto the coke cake without any further distribution into the gas-filled primary heating chamber or horizontally without any further conduction or direction onto the coke cake, if the primary air streams in laterally. This causes a non-uniform distribution of primary air in the gas-filled space above the coke oven chamber whereby the partial combustion of coking gas with primary air takes a worse course and whereby the temperature distribution in the upper part of the coke oven chamber becomes non-uniform. This entails a substantially increased burden of gases containing nitric oxides of the NOx type on combustion of coking gas with primary air.
In some layouts of coke ovens, a fan is installed into the air supply openings for coal in order to support the air admittance of primary air into the combustion gas space. An example is taught by GB 341157 A. Other designs, in turn, utilize an air supply system that collects the air for a coke oven battery or a coke oven bank and feeds it in dosed quantities to each individual coke oven. For example, this can be accomplished by suitable control elements or regulating elements in the individual air supply ducts for the individual coke oven chambers. In this manner, the supply of air is made independent of weather impacts. An example is taught by EP 1893721 A1. However, the layouts and designs outlined hereinabove merely alter the efficiency of the outer air supply for coke ovens while they do not solve the problem of an insufficient air distribution in the opening-remote areas of the combustion space above the coke cake.